Vin is a melee support and tank from the Void. He doesn't use mana as a resource, but health, specifically current health. His ability set makes him more dangerous as he gets lower on health, so items such as Hexdrinker will benefit his playstyle.

His Q is a toggled on-hit effect. In applies infected wounds, which is in sense an aggressive counter to heal supports like Soraka.

His W is a burst heal. It has a long cooldown, and isn't that useful to an ally at near full health. It's most useful at saving low health allies, but the long cooldown on it will prevent multiple casts within the same teamfight.

His E provides useful mobility and displacement, and is stronger at higher health, making it a good initiate.

His Ultimate provides a ton of utility, and I intended it to let Vin turn the tide of a 1v1 in Top Lane while still in bottom lane. The passive on the ult also lets him stay at low health easier, while still being able to be bursted down.

Toggle:? Vin’s autoattacks burn his targets, dealing additional magic damage based on his missing health. Also inflicts targets with infected wounds. Targets affected with infected wounds gain no effects from heals and regeneration effects, and take magic damage whenever they are healed, equal to 50% of the heal.